98 Spx off idle hesitation clarification

[DaddyLoafin]

98 Spx has a hesitation when you go full throttle just off idle for a split second than takes off.

I just set the carbs back to factory specs. All genuine Mikuni parts. Pop off is 39psi in each carb, low speed screws are at 1 1/2 turns out, high speed screws are closed and accelerator pump is squirting fuel into each carb as it should, rotary valve clearance is 0.011. Playing with the choke while it does the hesitation makes it worse and stall, so I assume it’s running rich. And it will start up cold immediately with one touch of the starter button without any choke or touching the trottle at all, even if it’s in the water.

My question is; will closing the low speed screws help get rid of this? I’ve read conflicting things and I’ve had the carbs off 5 times in the last week and am hoping to avoid doing that again lol.

 

[fatblockabody]

https://www.mikuni.com/pdf/sbn_manual.pdf

^^ That link was super helpful in helping me initially learn these carbs. Groupk has some good info on their site as well. Do you have an aftermarket flame arrestor?

Edited because I verified info on seadoosource that I was pulling from memory. 1998 OEM carb settings are different than my '97 (wonder why?)

 

[DaddyLoafin]

probably should have mentioned the engine is completely stock. Fresh spark plugs with a 0.032 gap. Compression is 145pto 150mag but the pto had a melted bellow on the rave valve when I did the test so Idn if that affected the reading.

Before I changed the springs on the carb it was set to around 30psi and like 3/4 turn out on the low speed but it wouldn’t idle for very long and the needle valves were leaking causing a hot start issue.

 

[DaddyLoafin]

https://www.mikuni.com/pdf/sbn_manual.pdf

^^ That link was super helpful in helping me initially learn these carbs. Groupk has some good info on their site as well. Do you have an aftermarket flame arrestor?

Edited because I verified info on seadoosource that I was pulling from memory. 1998 OEM carb settings are different than my '97 (wonder why?)

Appreciate the link. And it might be because of the accelerator pump

 

[POPPS]

Accelerator pump can cause your issues.,,,check compression to start.

 

[mikidymac]

It also depends on how you are operating the throttle.

On these skis you can’t just go from idle and no throttle, instantly pin the throttle wide open and expect it to not bog. It takes some time for the intake vacuum to build and the carbs to start flowing the correct fuel even with the accelerator pumps.

It could be you have a problem or you might just expect more than these carbs can do.

 

[DaddyLoafin]

Ahh it’s probly just me. I’ve been going from idle to full throttle. My other ski is a gp1300r so my expectations are probably to high for the carbs.
I closed the low speed screws some last night and it took out a lot of the hesitation and the idle smoothed out a lot. By far the best it’s ran In my ownership of it.
I checked compression 2 or 3 weeks ago and it was 145 on the pto and 150 on the mag. The pto side rave valve had melted its bellow and I hadn’t noticed that yet when I did the compression test. So Idn if that’s why it was lower or not.